Yes, to a certain extent. The dimensions of your model can be up to 2 km in each dimension, which should be enough to model a street section or a small city block for instance.

In an outdoor scenario, many rays will escape from the model, so you should make sure to use a large number of late rays to compensate for this loss. Since ODEON 18 there is no need to place the geometry in a bounding box (as it was required in the older editions), but only setting the maximum lost rays to 100% in the Room setup.

Note that wind and temperature gradient effects are not included in ODEON simulations. These can have a significant effect outdoors, but they are usually of less importance in the scale allowed in ODEON.

Please note that ODEON is one the few packages in the market that allows you to combine outdoor and indoor simulations with the use of transmission in a project. For example, you can calculate how much traffic noise enters a building, followed by its effects to the interior acoustics.

You can find some useful tutorials on outdoor simulations with ODEON here.